1. Field of Invention
The present invention relates to a casing structure having a removable base frame, and more particularly to a casing structure having a removable base frame applicable to an expansion card.
2. Related Art
In recent years, the number of Internet users is growing at a multiplying rate every year. Companies and other organizations set up their own websites and servers one after another, hoping that the customers can know the products and features of the companies without appearing in person, thereby bring infinite business opportunities for the companies.
Currently, a common server includes a mainboard, and one or more expansion cards are inserted on the mainboard according to users' specific requirements to perform specific functions. For example, a network card is installed on the mainboard of a server, such that the server functions as a web page server. After the web page server receives an instruction request from a client, the website server replies to the instruction sent by the client program.
As the cost of the servers increase and the available space reduces, most servers are mostly arranged uniformly in a cabinet in use, which are referred to as rack-mounted servers, so as to minimize the space occupied by the servers. In addition, since the servers are designed according to international standards, the planar dimensions are uniform, so the servers can be connected with or manage other equipment conveniently.
According to height, the servers are categorized into a variety of specifications such as 1 U (1 U=1.75 inch=44.45 mm) servers, 2 U servers, and 3 U servers. However, limited by the space of the rack and the current state of technology, 1 U servers are still the mainstream of the market. Therefore, the expansion card certainly cannot be easily inserted into or pulled out from the mainboard of the server as in an ordinary personal computer.
A conventional method for installing an expansion card on a mainboard of a server is to use both hands to simultaneously apply a force on two side of an expansion card module, so as to insert the expansion card into a connection port of the mainboard, and then secure the expansion card module on an electronic apparatus with screws. When it is desired to pull out the expansion card, the screws need to be screwed off first, and then a force is exerted on the expansion card module to pull out the expansion card module. Another conventional installation method is to fix the expansion card below a fixing module first. Then fixing module is in a suitcase-like form and is provided with a handle at an upper side. When the expansion card needs to be inserted into or pulled out from the connection port, a force is then exerted on the handle to insert or pull out the expansion card.
However, the prior art has the following problems. When it is desired to pull out the expansion card module, one end of the expansion card module may be under a relatively large force and the other end may be under a relatively small force due to an uneven force exerted by the user, such that the end under the relatively large force is first pulled out from the connection port. Thus, the expansion card is released from the connection port at an inclination angle rather than in a completely horizontal direction, or the user exerts a lateral force rather than a force perpendicular to the mainboard, either of which results in abnormal contact of the golden fingers of the expansion card with the connection port, thereby resulting in the damage of the golden fingers and abnormal operation of the expansion card after being installed on the mainboard. Furthermore, when the expansion card module is installed, additional screws are needed to secure the expansion card module to the electronic apparatus, thereby resulting in inconvenience in disassembly, assembly, and maintenance.